1. Field of Inventions
The present inventions relate generally to speech processors such as, for example, the speech processors in implantable cochlear stimulation (or “ICS”) systems.
2. Description of the Related Art
ICS systems are used to help the profoundly deaf perceive a sensation of sound by directly exciting the intact auditory nerve with controlled impulses of electrical current. Ambient sound pressure waves are picked up by an externally worn microphone and converted to electrical signals. The electrical signals, in turn, are processed by a speech processor, converted to a pulse sequence having varying pulse widths and/or amplitudes, and transmitted to an implanted receiver circuit of the ICS system. The implanted receiver circuit is connected to an implantable electrode array that has been inserted into the cochlea of the inner ear, and electrical stimulation current is applied to varying electrode combinations to create a perception of sound. A representative ICS system is disclosed in U.S. Pat. No. 5,824,022, which is entitled “Cochlear Stimulation System Employing Behind-The-Ear Speech Processor With Remote Control” and incorporated herein by reference in its entirety.
As alluded to above, ICS systems typically include an implantable device, a speech processor unit, a microphone that is in communication with the speech processor unit, and a headpiece that is in communication with both the speech processor unit and the implantable device. In one type of ICS system, the speech processor unit is worn behind the ear and, accordingly, this type of speech processor unit is often referred to as a behind-the-ear speech processor unit (or “BTE unit”). The BTE unit is typically secured to the user with a removable ear hook and, in many cases, a microphone is carried by the ear hook. An on-board microphone is also carried by the BTE unit itself. Another type of speech processor unit is the body worn speech processor unit (or “body worn unit”). The body worn unit, which is larger and heavier than a BTE unit, is typically worn on the user's belt or carried in the user's pocket. Microphones used in combination with body worn units are often incorporated into the headpiece.
The present inventors have determined that conventional ICS systems are susceptible to improvement. For example, body worn units are preferable to BTE units in the case of infants and toddlers. BTE units tend to be too big for infants, and toddlers tend to remove and/or damage BTE units. Body worn units, on the other hand, can be attached to a harness that positions the speech processor unit on the infant or toddler's back, where it is difficult for the infant or toddler to reach. A BTE unit may, however, be more suitable once the child reaches an age (e.g. 5 years) at which he or she is less likely to damage the speech processor unit. Parents must then purchase a second speech processor unit, which is quite expensive. Even in those instances where insurance coverage or government subsidy (collectively “insurance”) provides for two speech processor units, and the parents elect to receive a BTE unit in addition to the body worn unit, the body worn unit may be of limited utility once the child is old enough to switch to a BTE unit. Moreover, if the BTE unit is lost or damaged, the child will be forced to switch back to a body worn unit because there is no spare BTE unit.
The present inventors have also determined that adults face similar obstacles with respect to BTE units and body worn units. For example, many adults prefer the smaller BTE units for most everyday activities, but prefer body worn units for sports and other activities for which an ear hook mounted BTE unit is simply unsuitable. Here too, the user is faced with a choice—elect to obtain a BTE unit or a body worn unit through insurance and, if possible, purchase the other type of speech processor unit. Moreover, even in those instances where insurance provides for two speech processor units, the user will not have a spare BTE unit if he or she elects to obtain one of each. Users are also forced to carry both speech processor units with them if they intend to switch from the BTE unit to the body worn unit and back without returning home.